Change the "OK" button name in dialog-boxes?
Unfortunately this isn't something you have any control over. The window_manager.invoke_props_dialog function is defined in C here, and ultimately uses the wm_block_dialog_create function, which contains this:
uiBut *but = uiDefBut(
        col_block, UI_BTYPE_BUT, 0, IFACE_(&quot;OK&quot;), 0, -30, 0, UI_UNIT_Y, NULL, 0, 0, 0, 0, &quot;&quot;);

As you can see from IFACE_(&quot;OK&quot;), the text &quot;OK&quot; for the confirm button is hard-coded in the C source, so there's no way to override it short of rebuilding Blender from source.